Process for treating oils



Sept. 24, 1929. Q DUBBS 1,729,308

PROCESS FOR TREATING OILS Original Filed Sept. 24, 19 23 JFZQ. J

Patented Sept. 24, 1929 UNITED STATES PATENT OFFICE CARBON P. DUBBS, OF WILMETTE, ILLINOIS, ASSIGN OR TO UNIVERSAL OIL PRODUCTS COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF SOUTH DAKOTA PROCESS FOR TREATING OILS Application filed September 24,1923, Serial No. 664.410. Renewed August 3, 1928.

This invention relates to a process for treating oils and refers more particularly to a. method of subjecting a body of hydrocarbon oil in a still to direct contact with superheated steam for the purpose of distilling ofl' the light hydrocarbons and producing coke.

In the specific application of my inven tion, it is applied to that type of still known as a coking still wherein a charge of Oil, which may or may not have been previously treated, is subjected to a high temperature by means of a jet of highly superheated steam discharged into the body of the charge, and the distillation carried on until all the vapors have been taken off and a residue resembling coke remains, the ob ect being to produce two products; a light 0l l and coke. .The advantages of this method of heating will be apparent to those skilled in the art among which are:

The use of superheated steam in a coking still eliminates the danger of burning out the bottom or under sides of the still by the formation of hot spots where the still is heated by means of fire; the use of superheated steam in the body of the oil charge obviates the necessity of shutting down the apparatus due to the insulation of the bottom of the still, prey'enting the heat units from penetrating this insulation, this insulation being caused by the deposit of carbon thereon; the use of superheated steam gives a more uniform heat.

In the drawings:

Fig. 1 is a side elevational view, partly in cross section, of an apparatus suitable for carrying out my invention.

Fig. 2 is a side elevational view, showing my invention applied to a commercial cracking unit.

The still 1, which may be a horizontal shell still, as shown or may consist of a tube still or even a vertical still, is charged through the inlet line 2, controlled by valve' 3, with oil, which may or may not have been previously treated. The process may be operated either as a continuous or batch process. In case it is operated as a batch process, the still may be from one half to two thirds full.

The oil is heated by means of a superheated steam spray, injected into the body of the oil through the perforations in the pipe 4 placed therein and fed by means of the inlet pipe 5, and the amount of steam introduced controlled by means of the valve 6. It is understood that the perforated pipe 4 may be positioned either horizontally or vertically at any position within the still that will keep it in contact with the body of oil. Also that there may be a plurality of these steam pipes positioned at different levels Within the still and supplied with steam through the pipe 5. For the purpose of drawing off the coke accumulated in the shell, I provide a plurality of manholes 7. The still may be equipped with the usual vapor dome 8, safety valve 9 and vapor outlet pipe 10.

Referring now to the use of the still described in connection with a system for treating oil, and operating continuously, the pressure residuum is continuously Withdrawn from an expansion chamber 11, without being allowed to cool, and forced by means of the pressure on the system through the lines 12 controlled by valves 13 and introduced into the still 1. 'hen operating the process in this manner, the pressure maintained on the pressure residuum is reduced or may be released altogether, by regulating the valve 3 on the inlet line and a certain portion of the residuum will vaporize in the still 1 due to this release of pressure and the latent heat retained therein. The unvaporized portions are subjected to a constantly increasing heat maintained in the body thereof by superheated steam as explained.

When the process is operated as above, that is, as a continuous process, the length of operating depends on the quantity of carbon precipitated to the bottom of the still.

I may provide a residuum drawotf 14 controlled by the valve 15 for the purpose of withdrawing residuum if necessary or desirable, from the still 1.

From the foregoing description, it will be seen that I eliminate the danger of burning out the bottom of the still which has been a serious factor in a so-called coking still. In addition, the heating medium, being disposed in the body of oil, is not insulated from the body of oil by means of the coke. It will be apparent that the process can be operated for more extended periods of time then by previous methods. Thestill may be lagged as shown at 16 to prevent radiation of heat.

One method of operation would be as follows: When crackmg hydrocarbon oils to roduce lighter products such as gasoline and the like by the use of heat and pressure, a certain amount of residuum is produced which is called pressure residuum. This pressure residuum while still in a heated condition, is introduced into the still 1 through the line 2 the pressure being reduced to sa atmospheric, by means of the valve 3. I certain amount of this residuum will vaporize under its latent heat as the pressure is released. The still unvaporized portion is subjected to a higher heat say, as 111 h as 1500 degrees F. if necessary and all the vaporizable constituents distilled therefrom so that the residue is a coke which is precipitated to the bottom of the still. The length of the operation Will be regulated by the amount of coke deposited on the bottom. In other words, when the carbon has accumulated to an extent that will impair or slow up the operation, the steani will be turned ofi and the still allowed to cool.

It will 'be understood that I may allow any fraction or all of the oil to be distilled ofi'. In place of the steam, I may introduce an extraneous gas which will not have an undesirable reaction on the oil charge.

I claim as my invention:

1. A process for treating unvaporized residual oil accumulating during the cracking of h drocarbon oil consisting in withdrawing the ighly heated oil from the reactin zone of an oil cracking process, and in intro ucing the same to a coking still, in releasing the pressure on said oil in the coking still, and in applying heat to said oil to distil fractions thereof and to run the residue down to coke only by passing super-heated steam through said oil.

2. A process for treating residual oil which accumulates in the reaction zone of an oil crackin process residua oil from the reaction zone of the oil cracking process wherein it is produced, introducing the same to a coking still releasing pressure on the oil in the coking still and distilling the residual oil down to coke in said coking still by heating the oil therein solely by passing superheated steam through the residual oil in said cokin still.

CAR ON P. DUBBS.

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